It’s recommended that kits be kept between 5 C and 25 C, as officials said allowing them to freeze or to get too hot can diminish the potency of the medication.

This means more doses could be required to effectively reverse an overdose.

“Allowing these kits to get too hot or too cold doesn’t necessarily mean they won’t work, but more than one dose may have to be administered and not everyone carries around more than one, it becomes very inconvenient” said Allert.